I'm in the military and we have to pass a physical fitness test twice a year. I can either run or swim. Since I have a fear of deep water and have failed many attempts to learn to swim, I am stuck with running. If running is going to have severe long-term effects, then maybe it isn't worth it. I would like to stay in another 3 years and retire, but I don't know if I can cope with the pain I get for days after running. I've never been a good runner and I have grown to loathe running because of this. Are the effects mild enough to force myself through it or am I causing irreversible damage by continuing to run and not take a stand against it? Docs tell me running is bad, then say I have to anyway.